**Minimum Updates to Make Bitwise OR Equal to Target - Microsoft Top Interview Questions**

### Problem Statement :

You are given three positive integers a, b and target. Consider an operation where you take either a or b and update one of the bits to 1 or to 0. Return the minimum number of operations required to make a | b = target. Constraints 1 ≤ a, b, target < 2 ** 31 Example 1 Input a = 2 b = 4 target = 8 Output 3 Explanation 10 = a 100 = b 1000 = target We need to first unset a and bs 1 bits to make them zero. Then we can set a directly to 8.

### Solution :

` ````
Solution in C++ :
int solve(int a, int b, int target) {
int ans = 0;
for (int i = 0; i < 32; ++i) {
int mask = 1 << i;
if (target & mask) {
if ((a & mask) || (b & mask)) continue;
ans++;
} else {
if (a & mask) ans++;
if (b & mask) ans++;
}
}
return ans;
}
```

` ````
Solution in Java :
import java.util.*;
class Solution {
public int solve(int a, int b, int target) {
int aExtra = a & ~target;
int bExtra = b & ~target;
int targetExtra = target & ~(a | b);
return Integer.bitCount(aExtra) + Integer.bitCount(bExtra) + Integer.bitCount(targetExtra);
}
}
```

` ````
Solution in Python :
class Solution:
def solve(self, a, b, target):
res = 0
while a != 0 or b != 0 or target != 0:
if (a & 1) | (b & 1) != (target & 1):
res += 1
if (a & 1) == (b & 1) == 1:
res += 1
a >>= 1
b >>= 1
target >>= 1
return res
```

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